An EdmFunctionAttribute links a common language runtime (CLR) method to another function. For example, the attribute can be used to map a CLR method to a function that is exposed by the storage provider, to a user-defined function in the database, or to a user-defined function in the conceptual model. Methods that have this attribute can be called from LINQ to Entities queries.

To use an EdmFunctionAttribute to map a CLR method to a function, the following must be true:

The return type of the CLR method must be compatible with the return type of the mapped-to function.

The argument types of the CLR method must be compatible with the argument types of the mapped-to function.